Conventionally, an air spring used for a vehicle such as a railroad vehicle has been known (see Patent Document 1, for example). Such an air spring is provided between a vehicle body and a carriage of the vehicle to reduce impacts and vibrations applied to the vehicle body during traveling of the vehicle. Accordingly, the load of the vehicle body is exerted onto the air spring mainly in the vertical direction. The direction in which the load of the vehicle body is mainly exerted onto the air spring is defined as a main load direction in the present specification. The main load direction is substantially in parallel with the vertical direction.
The air spring includes an assembly for air spring and a diaphragm. The assembly for air spring is assembled on the carriage side of the diaphragm, for example. The air spring can reduce impacts and vibrations in the main load direction during traveling of the vehicle.